Antioxidants 'cannot slow ageing'

ISLAMABAD: There is probably no easy way to combat ageing. Diets and creams claiming their antioxidant properties could cheat ageing may be worthless, a study says.

Using Nematode worms, scientists found even those given enhanced antioxidant powers to deal with tissue damaging "free radicals" did not live longer.

The team from University College London said, in the Genes and Development journal, there was "no clear evidence" they could slow ageing. Antioxidants are a staple of the beauty and health industries. This has been based on a 50-year-old theory.

The free radical theory has filled a knowledge vacuum for over 50 years now, but it doesn't stand up to the evidence In 1956, it was suggested that ageing was caused by a build-up of molecular damage caused by reactive forms of oxygen, called superoxides or free radicals, circulating in the body. This is known as oxidative stress.

Antioxidants supposedly worked to mop up these free radicals, minimising their damage. This week's study, however, could explain why many studies aimed at proving the theory have been inconclusive. The tiny Nematode worm, despite appearing to be far-removed from the human species, is a useful tool for scientists who want to explore how our bodies work.

They share many genes with humans, and, crucially, have a lifespan measured in days, which allows scientists to get clues about long-term changes.

The UCL team, led by Dr David Gems, genetically manipulated nematodes so that their bodies were able to "mop up" surplus free radicals.

This is theory, should give them an advantage over normal nematodes in terms of ageing and lifespan.

However, these worms lived just as long as the others, suggesting that "oxidative stress" is less of a factor in the ageing of our cells and tissues as some have suggested.

Dr Gems said: "The fact is that we don't understand much about the fundamental mechanisms of ageing - the free radical theory has filled a knowledge vacuum for over 50 years now, but it doesn't stand up to the evidence.

"It is clear that if superoxide is involved, it plays only a small part in the story - oxidative damage is clearly not a universal, major driver of the ageing process."

He said a healthy, balanced diet was important for reducing the risk of many "old age" diseases, such as cancer, diabetes and osteoporosis, but there was no clear evidence that eating antioxidants could slow or prevent ageing, and even less evidence to support the claims made by antioxidant pills and creams.

The research was supported by the Wellcome Trust, and Dr Alan Schafer, its head of molecular and physiological sciences, said: "Research such as this points to how much we have to learn about ageing, and the importance of understanding the mechanisms behind this process."

A spokesman for the British Dietetic Association said that it had been hard to find the evidence to support antioxidants from previous studies.

She said: "All the evidence has come from epidemiological studies looking at the whole diet - where there was some sign of benefit to people who ate diets with antioxidants, but also who ate lots of other good things.

"What this shows is that there is likely to be no one 'magic bullet' in terms of diet and health -the important thing is still achieving a healthy balance."

A spokesman for the Cosmetic Toiletry and Perfumery Association said cosmetic companies carry out extensive research and rigorous scientific studies to ensure claims are supported by robust evidence.

"Findings on the genetics of a particular nematode worm may not be directly relevant to the complex process of ageing as it happens in higher animals such as the human," the association added.

Contact Lens Cases Often Contaminated: Contamination is common in contact lens storage cases, say Israeli researchers who found at least one pathogen in two-thirds of 30 storage cases used by 16 people.

The tests of contact lens disinfection solution in the storage cases found that Pseudomonas — a known cause of severe corneal infections — was the most common type of pathogen (41 percent), while fungal pathogens accounted for about 3.3 percent of contamination.

Pathogens were found in all the types of storage solutions examined in the study, and some of the solutions tested positive for pathogens every time they were tested. These pathogens can cause keratitis, an often painful inflammation of the cornea. Complications from keratitis can lead to vision loss.

The findings were presented at a recent joint meeting of the American Academy of Ophthalmology (AAO) and the European Society of Ophthalmology.

"The picture that arises from this study is disturbing," wrote Dr. Assaf Kratz and Dr. Tova Lifshitz of the Soroka Medical Center. "It seems that the commonly used disinfecting solutions provide little protection from contamination of contact lens storage cases."

The researchers advised contact lens users to closely adhere to contact lens care guidelines, including frequent cleaning and replacing their lens case regularly in order to prevent contamination.

About 24 million people in the United States use contact lenses. If contact lenses aren't properly cleaned and disinfected, there's an increased risk of severe eye infection. Any lens that's removed from the eye needs to be cleaned and disinfected before it's reinserted. Care of contact lenses includes cleaning the storage case, since it's a potential source of infection, the AAO said.

But this risk is no greater than other treatments for cancer treatment-related anemia, the scientists said, after having analyzed data on more than 70,500 cancer patients who received transfusions at 60 medical centers from 1995 to 2003.

Of those patients, 7.2 percent developed venous thromboembolism (VTE), and 5.2 percent developed arterial thromboembolism (ATE), compared with rates of 3.8 percent and 3.1 percent, respectively, among patients who didn't receive transfusions.

The study was published in the latest issue of the journal Archives of Internal Medicine.

End.

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